It has been shown that children diagnosed as having early infantile autism suffer from severe handicaps in understanding and using language. These handicaps may relate to difficulties in discriminating speech sounds from non-speech sounds or in decoding and encoding material received though auditory channels. The present investigation proposes to study electrophysiological correlates of auditory discrimination in autistic children. Stimuli will consist of words and musical chords, the cortical responses to which will be studied using a stepwise discriminate analysis method operating upon pre-processed single response EEG data. These methods will yield an Event-Related Information Wave indicating the accumulation of experiment relevant information in space (electrode location or the scalp) and time (in relation to stimulus onset). Questions to be studied include: what is the temporal distribution of the arrival of information over each cortical area, and is the temporal arrival of information in autistic as compared to normal and mentally-retarded comparison subjects. The ultimate goal of the project will be to further our understanding of the pathophysiology of early infantile autism with a view toward improving our methods of identification and treatment.